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Another title match has suddenly been added to the Royal Rumble show

Another title match has been added to the Royal Rumble event.

WWE United States champion Bobby Roode announced the first ever "Glorious U.S. Open Challenge"  on Friday via Twitter.

The open challenge will take place Sunday during the the Royal Rumble Kickoff show, prior to the company's first of its four major pay-per-view events of 2018.

The full match card will now include five title matches, having already scheduled matches for both the RAW and SmackDown Live tag-team championships, the WWE championship and the Universal championship.

Roode defeated Jinder Mahal in the final round of United States championship tournament two weeks ago to win the title and will be defending it for the first time.

The United States championship has been defended in open challenges during past reigns, beginning with John Cena's run in 2015 following WrestleMania 31.

Cena's challenge included numerous highlights, including the main roster debuts of both Sami Zayn and Kevin Owens, who instead attacked the champion and went on to defeat him in a non-title match during his in-ring debut at Money in the Bank 2015 nearly two weeks later.